Environmental

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It is nice to be able to moor one’s boat at the bottom of the garden. Some gardens are bigger than others. Take Castle Howard in Yorkshire, and its Great Lake, the venue, some ninety years ago, for sculling races, with a lakeside boathouse built for just that purpose. Then nothing - until recently when Estate Manager, John Major (no, not the PM!) decided it would be good for business to have a tripboat on the Great Lake and convert part of the derelict boathouse to a cafe.

Through marine surveyor, David Raggett, a wooden boat, 18ft6” x 5ft, recently and beautifully built at the Lowestoft Marine College, was located and purchased. Whilst arrangements were made to fit it out with a “Surrey with the fringe on top”, the search was made for a quiet and operationally simple propulsion unit, John Major decided to “cruise electric”. Rejecting STAELCO’s package as too expensive, he heard about Cedric Lynch and Electro Marine Technology.

By October Cedric had just about completed the motor with everything thickly painted to protect against corrosion... “And I think I have cracked the problem of how to make brush-holders in a reasonable length of time.”

A drizzly mid-October, Cedric drove his van up to Yorkshire, taking with him the completed motor, some car batteries for doing tests and some old telephone exchange 2-volt cells. It turned out that the boat had a box in it, into which those cells fitted perfectly.

“When I got there, the boat was at Mowthorpe Hill farm a few miles away, under a roof on stilts, a sort of a barn. I fitted the motor into it there.” Cedric also took the propeller shaft to a local engineering firm Park Engineers in Malton, to have it machined to fit the pulley, by means of a keyway.

The three-bladed propeller (16-inch diameter x 16 inch pitch) was specially made for the project. Lynch had also made an engine-bed out of steel-tube and angle-iron. Drive is via an 8mm pitch HTD-type toothed belt, pulleys 24 and 72 teeth, to the propshaft with a reduction of 3:1. With the motor
spinning at 800rpm, prop speed of just under 300rpm propels the 1-ton boat at 3.5 - 4 mph. Remarkably the amount of power needed to drive the boat is less than 300 watts. The supply is a 6 volts and the current taken is 40-50 amps when moving and 60-70 amps if the boat is held stationary.

“It is in fact getting quite a bit less than that because I have discovered that the friction on the seal is such that it takes 45 watts just to turn the shaft. Manufacturers need to do something about that to make electric boats better.”

To transport the boat, the Estate farmer arrived with his JCB Load-All Farm Special, a variety of giant forklift truck mounted on four tractor wheels. Using a couple of big slings, this now lifted the boat up and put it onto the trailer, then towed it from the farm to the Great Lake at Castle Howard. Lifting it off the trailer with the forklift, the JCB just drove down the bank of the lake and effortlessly lowered the boat into the water.

True to form, the Lynch approach worked quite satisfactorily. Given that less than 300 watts of electrical power is required to propel the boat, Cedric has calculated that just six Solarex photovoltaic panels will run it beautifully - fitting onto the planned Surrey Top with plenty of space to spare. Castle Howard are now considering this option.